Abrasive throwing machine



Aug. 29, 1939. v. E. MlNlH '2,170,831

ABRASIVE THROWING MACHINE original Filed May '25, 1934 2 sheets-sneet 1 ATTORNEYS A ug. 29, 1939. v. E. MlNlcH ABRASIVE THROWING MACHINE Original Filed May 25. 1934 2 Sheets-Sheet 2 INVENTOR l/eme//u/t BYM K AITCRNEYS Patented Aug. 29, 1939 ABRASIVE THROWING MACHINE Verne E. Minich, Scarsdale,`N. Y., assigner to The American Foundry Equipment Company, Mishawaka, Ind., a corporation of Delaware Application May 25, 1934, serial No. 727,398 Renewed November 25, 1938 6 claims.

Ihis invention relates to centrifugal abrasive throwing machines and more particularly to apparatus for directing and controlling the abrasive thrown by the machine.

This invention comprehends the provision of devices adapted tobe associated with an abrasive throwing machine whereby the abrasive thrown may be controlled particularly as respects to the direction of ight, area covered by the thrown 0 abrasive, and .intensity of impingement. The

machine generally comprises a rotatably mounted rotor which may be made with spaced rotatably mounted discs having removable and replaceable throwing blades radially arranged therebetween. The blades are preferably shaped to contain the abrasive entirely within the area of the blade and out of wearing contact with the permanent parts of the machine. The blades preferably extend short of the center of the machine so as to providea center inlet through which the -abrasive feeding means may be inserted. The abrasive may be conveyed to 4the Amachine through asuitable feed pipe in which the abrasive is moved either by gravity, air blast, screw conveyor or other means. A discharge nozzle is adjustably connected to the end of the feed pipe, extends into the center inlet and directs the abrasive substantially radially across the 'inner ends of the throwing blades.

The direction in which the abrasive is thrown from the machine depends upon the point at which the abrasive' is fed into the path of the rotating throwing blades. By adjusting the position of the discharge opening of the feed nozzle the abrasive may be thrown in .any clesired direction. The length of the path swept bythe thrown abrasive is determined by the peripheral length of the discharge opening in the feed nozzle. Means are provided for adjusting the peripheral length of the discharge opening in the feed nozzle, and thereby controlling and regulating the length of the path swept by the thrown abrasive.

The intensity of abrasive impingement against the work is determined by the peripheral length of the discharge opening in thefeed nozzle and by the volume of abrasive fed through the nozzle. If the peripheral length of the feed nozzle is increased the volume of abrasive fed into the machine must be proportionately increased to obtain the same or greater intensity of impingement. To feed thel maximum volume of abrasive through an opening of given peripheral length requires that the opening have an axial width .substantially as great as the width of the throwing blades. The control device may be abjusted to adapt the machine to a variety of different operating con.-

ditions. Y

An object of this invention is to provide a centrifugal abrasive throwing machine having means by whichv thrown abrasive may be directionally controlled so that the" desired work area vwill be impinged thereby.'

Another object of this invention is to provide an abrasive throwing rotor and associated means whereby the area covered by the thrown abrasive maybe regulated and controlled.

Still another object of this invention is to provide an abrasive throwing rotor and associated means for regulating and controlling the intensity of impingement of the thrown abrasive.

Another object of this invention is to provide a rotor for throwing abrasive at blasting velocities provided with means for regulating and controlling the direction of iiight, the intensity of impingement, and the area covered by the thrown abrasive.

Another object of this invention is to provide an abrasive throwing machiie adapted to be adjusted to eifectively clean and abrade under varying operating conditions articles and objects which vary in shape, hardness and surface char- 'acteristics Another object of 'this invention is to provide an abrasive throwing machine Whichis simple in construction, which has a low power consumption for the work done, which imparts to the abrading a highly effective abrasive velocity, which causes a minimum disintegration of the abrasive particles, which is durable and lasting in construction, which is not subjected to excessive Wear fro'm'the abrasive whenthrown from the machine, and which is highly effective for the cleaning of metal sheets, billets, castlngs, forgings and other metallic objects.

Other objects of this invention will become apparent as the disclosure proceeds.

invention may be had, attention is hereby directed to the drawings forming a part of this application, and illustrate certain possible embodiments of my invention.

Referring to the' drawings:

Fig. 1 is a longitudinal cross sectional view of my abrasive throwing machine showing the interior construction thereof, this view being taken on line I-I of Fig. 2. I

Fig. 2 is a transverse cross sectional view through the machine, this view being taken on line 2--2 of Fig. 1. Fig. 3 is a diagrammatic view illustrating the direction of movement of the abrasive thrown from the machine when the discharge end of the feed nozzle is positioned as shown.

Fig. 4 is a longitudinal cross sectional view of the abrasive throwing Wheel equipped with an abrasive control device of modified construction, certain parts being broken away to more clearly illustrate certain features or the control device.

Fig. 5 is a transverse cross sectional` view through the machine and through the abrasive control device shown in Fig. 4, this view being taken on line 5 5 of Fig. 4; and

Fig. 6 is a top plan view of the abrasive control device shown in Figs. 4 and 5.

Similar reference characters refer to similar parts throughout the several views of the drawings and specification.

Referring more particularly to Figs. 1 and 2, the abrasive throwing machine comprises a wheel or rotor which may be formed from spaced plates or discs I and 2 joined together by radially extending vanes 3. The rotor is suitably mounted upon a shaft il which is fixed to the hub extending from the disc I. Removable and replaceable blades b of generally channel form rest upon the vanes 3 and may be held in position by means of a set screw 6 which extends through the plate 2 and engages with the side of the removable blade. Any well known means, however, for securing the throwing blades in position may be used within the contemplation of this invention. 'Ihe radial supporting vanes 3 and the throwing blades b extend short of the center of the rotor providing an open chamber or center inlet c centrally of the machine.

A feeding device is provided which extends through an opening III) cut through the center of the disc 2 and extends into the center inlet c. The feeding device comprises a feed pipe 'I which conducts the abrasive to a feed nozzle I I adjustably mounted on the end of the pipe'l. A screw conveyor comprising the helical vane 8 supported by the 'core 9 may be used to move the abrasive through the pipe 1. Aspider Il) may be fixed within the end of pipe I to rotatably support .the core 9 of the screw conveyer. Other means for feeding the abrasive into the feed nozzle II such as air blast, gravity, or both may also be used within the contemplation of this invention.

'I'he feed nozzle I I is provided with a discharge opening I2 in the end thereof which is positioned adjacent to the inner ends of throwing blades b. The axial width of the discharge opening I2 is not greater and preferably less than the axial width of the throwing blades b and is so shaped as to direct the abrasive into the channel groove in the blades and out of contact with the side wall discs I and 2 of the machine.

The feed nozzle I I is adjustably mounted so as to permit the discharge opening I2 thereof to be placed in any position within th'e center inlet c, as diagrammatically illustrated in Fig. 3. The attaching end of the feed nozzle is provided with a collar portion I4 which seats against a collar portion I5 extending around the end of the feed pipe 1. The feed nozzle Il is provided with a flanged portion I6 which extends around the collar portion I5 of the feed pipe 1 and retains the feed nozzle I I in position. A set screw I1, extending through the flange portion I6 and engagingthe collar portion I5, may be used to retain the feed nozzle II in any desired adjusted position. Other means for adjustably securing the feed nozzle II to the end of the feed pipe 'l may be used.

A throwing machine having a diameter of approximaely 20 inches and rotated at approximately 2,200 revolutions per minute will effectively abrade and clean metallic castings, forgings, billets, metal sheets and other metallic objects. When the discharge opening I2 of the feed nozzle II is positioned at approximately the 12 oclock position, a rotor 20 inches in diameter operating at 2,200 revolutions per minute will discharge the abrasive a from approximately the 4 oclock to the 8 oclock positions as illustrated in Fig. 3. With a given machine rotated at a specified R. P. M. the direction of discharge will be determined by the position of the discharge opening I2 of the feed nozzle. The abrasive can, therefore, be thrown in any desired direction by swinging the nozzle II around to the proper position and securing the same in this position by means of the set screw Il.

The discharge end I2 of the feed nozzle II is fixed so as to direct the abrasive substantially radially across the inner ends I3 of the throwing blades b thus injecting the abrasive into the path of the moving blades when rotating at a high velocity.

The length of the path swept by the thrown abrasive is determined by the peripheral length 0f the discharge opening I2 of the feed nozzle. With a discharge opening of fixed peripheral length, the path swept by the thrown abrasive will be substantially uniform in machines of the same diameter rotating at approximately the same speeds. With a given discharge opening the intensity of impingement depends upon the amount of abrasive fed through the machine per minute.

The length of the path swept by the thrown abrasive can be varied in a given machine by changing the peripheral length of the discharge opening in the feed nozzle.

There is shown in Figs. 4, 5 and 6 a modified form of V-shaped discharge nozzle in which the size and peripheral length of the discharge opening is varied as desired by means of one or more sliding shutters 3| which may be moved to enlarge or reduce the size of the discharge opening. The shutters 3| may be slidably retained in position by the yprovision of rolled edge portions 34 which slidably grip rim portions 33 extending outwardly from the top edge of the side walls 20 and 2 I. A suitable handle 32 may be provided for manipulating the sliding shutters 3l. The nozzle may be`provided with fixed end walls 22 and 30 or the end walls may be made radially movable. The length of path swept by the thrown abrasive may be regulatedby adjusting the sliding shutters 3| into the proper position. Directional control of the thrown abrasive may also be effected by swinging the discharge end of the nozzle into the proper position and securing the same in this position by means of the adjusting screw I1. When this type of nozzle is used, the direction of flight of the thrown abrasive, as well as the length of path swept by the abrasive, may be varied as desired without requiring a change of nozzles.

Where a V-shaped nozzle is used, it may be advisable under certain operating conditions to augment the conveyer or gravity feed by a low pressure stream of air. As illustrated in Figs. 4, 5 and 6, the discharge end 36 of the air pipe 35 extends through the bottom portion 23 of the nozzle. A screw conveyer or gravity is used to carry the abrasive to the nozzle, at which point the .air blast emitted from the discharge end 36 of the air pipe 35 blows the abrasive through the nozzle and distributes the abrasive so as to obtain a substantially uniform intensity of discharge throughout the cross-sectional area of the nozzle discharge opening. The discharge end 36 of the air pipe is so shaped to effectuate this result, The abrasive control device illustrated in Figs. 4, 5 and 6 is adapted to be associated with any suitable bladed rotor, and by way of example only it is shown associated with a bladed rotor of the type heretofore described in connection with Figs. 1 and 2.

With a machine as above constructed the abrasive can be thrown in any desired direction so as to impinge the desired work area and perform effective work. The direction of discharge is controlled by adjusting the .discharge opening in the feed nozzle to the proper position. The length of path swept by the thrown abrasive can be regulated by the use of a feed nozzle having a discharge opening of the required peripheral length. Where a discharge nozzle as shown in Figs. 1 and 2 is used, the nozzle is preferably removable and replaceable so that nozzles of different peripheral lengths may be used interchangeably in association with the same rotor. All of the discharge nozzles are preferably adjustably mounted so that they may be easily replaced when Worn. vWhere only one type of work is to be cleaned by the machine, nozzles having discharge openings of fixed peripheral lengths are satisfactory. Under conditions where it is desirable to change the length of path swept by the abrasive at intervals, a feed nozzle having an adjustable discharge opening, such as shown in Figs. 4 to 6, inclusive, may be preferable. The abrasivemay be propelled through the feed nozzle by means of gravity, conveyer, low air blast, or a combination of one or more of these. The discharge opening in the air nozzle is preferably so arranged as to direct the abrasive substantially radially across the inner ends of the blades. All of the abrasive fed into the machine is thus directed into the path of the moving blades and swirling of the abrasive within and around the machine is prevented. The axial width of the discharge opening is no greater and preferably less than the width of the throwing blades and is so shaped as to direct al1 of the abrasive within the confines of the removable throwing blades and out of contact with the permanent side plates I and 2 of the machine.

While certain novel features of the invention have been disclosed and are pointed out in 'the annexed claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

1. In a rotor for throwing abrasive at blasting velocities comprising, a plurality of spaced throwing blades mounted for high speed rotation about a common axis, said blades extending inwardly short of said axis of rotation to provide a center inlet, a feed pipe, a nozzle positioned within said center inlet and adjustably` mounted on said feed pipe for directing the abrasive discharge, means in said feed pipe for conveying the abrasive to said nozzle, and means for forcing the abrasive through said nozzle and into the path of movement of said throwing blades 2. A centrifugal machine for throwing abrasive at blasting velocities including, a plurality of spaced throwing blades mounted for high speed rotation about a common axis.' said blades extending inwardly short of said axis of rotation to provide a center inlet, a tubular control member having a discharge opening arranged to direct the abrasive substantially into the path of rotation of said blades, and a combination screw conveyor and air blast means for forcing the abrasive into said control member and out through the discharge opening therein. l

3. A centrifugal machine for throwing abrasive at blasting velocities including, a plurality of spaced throwing blades mounted for high speed rotation about a common axis, said blades extending inwardly short of said axis of rotation to provide a center inlet, a tubular control member having a discharge opening arranged to direct the abrasive substantially radially into the path of rotation of said blades, and a screw conveyor extending into said tubular control member with the inner end thereof extending inwardly short of the discharge opening, said screw conveyor being operative to extrude a core of abrasive from the discharge opening in said tubular control member.

4. An abrasive throwing machine. including, a rotatable side wall member adapted to be rotated ,at high peripheral speed, a plurality of spaced throwing blades supported upon said member, an abrasive control device for feeding abrasive onto the inner ends of said blades as they successively arrive at a predetermined point during rotation, said feeding device having a discharge opening and guide walls for directing the abrasive onto the inner ends of the blades substantially radially f said blades, and air blast means for forcing the abrasive outwardly through said opening and into the path of rotation of the inner ends of said blades, said air blast means including an air inlet in said control member `pointed in the direction of said discharge opening and in a direction generally radially of said blades for introducing a flow of air under pressure to carry the abrasive in the direction of said discharge outlet and generally radially of said blades.

5. A centrifugal device for throwing abrasive at blasting velocities including. a rotor having a plurality of spaced, radially extending, throwing blades extending short of the axis of rotation of said rotor to define a central space, a tubular control member for feeding abrasive toward said blades in a direction transversely of the path of rotation of said blades and having a dischargev opening arranged to direct the abrasive substantially radially into the path of rotation of said blades, and air blast means for forcing the abrasive outwardly through said opening and into the path of rotation of the inner ends of said blades whereby to control the direction of flight of abrasive thrown by said rotor, said air blast means including an air inlet in said control member pointed in the direction of said outlet and in a direction generally radially of said rotor.

6. A centrifugal device for throwing abrasive at blasting velocities including, a rotor having a plurality of spaced, radially extending, throwing blades extending short of the axis of rotation of said rotor to dene a central space, a tubular .control member for feeding abrasive to said blades in a direction transversely of the path of rotation of said blades and having a discharge opening arranged to direct the abrasive substantially radially into the path of rotation of said blades, and air blast means for forcing the abrasive upwardly through said opening and into the path of rotation of the inner ends of said blades, whereby to control the direction of ight of abrasive thrown by said rotor whereby it is ejected from the rotor in a generally. downward direction, said air blast means including an air inlet in said control member at a. point adjacent said outlet and pointed in an upward direction generally radially of said rotor for introducing a iiow of air under pressure under the abrasive moving into said control member. l,

VERNE E. MINICH. 

